A simple analytical technique, using a silieic acid minicolumn and capillary gas chromatography, was used for measuring the oxidative interactions of cholesterol vr other compounds. When triacylglycerols were added to cholesterol before heating at 1800C, the latter oxidized faster than cholesterol heated alone, and a relatively high amount of epoxides was found.Dipalmitoylphosphatidylethanolamine and all the amino acids tested showed a protective effect, with cysteine and alanine being the most effective. The results of this study indicate that the varius compounds added not only influenced the rate of cholesterol oxidation, but also exerted different influences on its oxidative pathway.

RESULTSIdentification of radiolysis products which are formed in lipids in the range of molecular weights from 400-600 has been established on the basis of gas chromatography/mass spectrometry (GC/MS) studies of long chain authentic samples of alkyl esters, ketones and propanediol diesters. This paper describes the GC/MS behavior of these compounds. Double hydrogen rearrangement was found to be the predominant ion in the spectrum of long chain saturated esters whereas in the unsaturated esters, a peak corresponding to the loss of alcohol from the molecular ion was more pronounced. On the contrary to short chain ketones, McLafferty rearrangement did not appear to be the major fragmentation in the spectrum of saturated and unsaturated long chain ketones, c~Cleavage was found to be the predominant fragmentation in the spectrum of these ketones. The "McLafferty + 1" rearrangement peak was more pronounced for the long chain ketones than those found in the spectrum of smaller ketones. Fragmentation patterns of propanediol diesters were shown to be similar to those in triglycerides, giving rise to predominant peaks corresponding to acylium ion [RCO] + and parent minus acyloxy ion [R-COO} +

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A detailed analysis has been made of the composition of radiolysis products formed in beef, pork, ham, and chicken. The yields of the various compounds are related linearly to irradiation dose, and the fat, fatty acid and triglyceride composition of the meats.